While her work duties might be covered, she's still figuring out how to keep things running smoothly at home - and when she'll fit in antenatal classes, being a first-time mother.

"We have talked about this a little bit - finding the time right now would be quite difficult. I have queried whether or not Clarke could do it for me and give me a quick executive summary, a few bullet points after each class."

They're also yet to decide on whose last name the baby will take - Ms Ardern and Mr Gayford aren't married, and even if they were, it's not clear who would take who's name if either did at all.

"I think Gayford-Ardern, Ardern-Gayford, it just becomes a bit of a mouthful," said Ms Ardern. "We'll find a way to put both in I think, somehow, without making it too complicated."